6.Method Statement for Concrete Repairs Rev. 1

Sinohydro Corporation Lusail Development Construction Package 1

Method Statement for Concrete Repairs

Lusail Development Construction Package 1

Employer: Qatari Diar Real Estate Investment Company


DOCUMENT REVIEW STATUS STATUS 1: WORK MAY PROCEED. STATUS 2: REVISE & RESUBMIT. WORK MAY PROCEED SUBJECT TO INCORPORATION OF COMMENTS INDICATED. STATUS 3: REVISE & RESUBMIT. WORK MAY NOT PROCEED. STATUS 4: REVIEW NOT REQUIRED. WORK MAY PROCEED.

ENGI ENGINE NEER ER’S ’S REVI REVIEW EW OF SUBM SUBMIS ISSI SION ON SHAL SHALL L NOT NOT RELI RELIEV EVE E THE THE CONT CONTRA RACT CTOR OR OF HIS HIS RESPONSIBILITIES UNDER THE CONTRACT.

________________________

HALCROW Date___________________

Amendment Records LD-CP1-SHC-MS-OW-005 LD-CP1-SHC-MS-OW -005 Rev. Rev. 1 30-Oct-2010

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Rev No.

0

1


Date

Amendment Record

Prepared By

Approved By

20 June 2010

General revision to incorporate all concrete repair procedures. First Version

Artemio T. del Mundo, Jr.

Li Binghan

Revised to incorporate new repair procedures for major concrete defects


Li Binghan

th

th

30 October 2010

LD-CP1-SHC-MS-OW-005 Rev. 1 30-Oct-2010

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Purpose....................................................................................................3 Reference Document...............................................................................4 Organization Chart and Responsibility................................................4 Error: Reference source not foundConstruction Arrangement.........5 Repair Methodology...............................................................................5 Measure and Plan for Safety and Health.............................................9 Measure And Plan for Environment Protection................................12 Quality Plan..........................................................................................12 Appendix...............................................................................................12

This Method Statement defines the methods required to execute concrete repairs at CP1 & LD-CP1-SHC-MS-OW-005 Rev. 1 30-Oct-2010

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supersedes the following document: Doc. No. LD-CP1-SHC-MS-CR-001 Rev. 3 “Method Statement for Concrete Repairs” & Doc. No. LD-CP1-SHC-MS-UT/R-007 Rev. 2 “Proposal for Repairing Cracks on Concrete Surface” •

•

Qatar Construction Specifications (QCS 2002) Section 5 Part 16.7.

, who reports to , will be incharge of the concrete repair works. He will coordinate with all concerned parties and ensure site repair works in time and with proper quality. , who reports to the concrete repairs quality.

, will be in-charge of

, who reports to the Technical Manager, will be incharge of the concrete repairs quality control. , who reports to the Project Manager and Sinohydro Head Office shall organize preparation and amendments or changes in QAP and other QM system documents and supervises their implementation and manages document control system of the project. who reports to the charge of the concrete repairs site safety & health.

will be in-

，

Their contact telephone numbers are enumerated hereunder:

1

Pan Jiliang

Construction Manager

5636816

2

Wang Wei

Section Manager

6094887

3

Zhu Jingping

Site Engineer

5035519

4


Quality Control Manager (QC)

5153175

5

Zhang Shuo

Deputy Quality Assurance Manager (QA)

6574881

6

Tommy

Safety and Health Manager

5699208

7

Kamal

Safety Engineer

6739709


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Error: Reference source not found • • • • • • •

- Approval Ref. No. GQ626/CP1/54/ad/0371 - Approval Ref. No. GQ/626/CP1/54/ba/1825 Approval Ref. No. GQ626/CP1/54/ba/6622 Approval awaited Approval awaited Approval awaited Approval awaited

1.2 • • •

Potable water Hessian Plastic Sheets

1.3 • • • • • • • •

Wire Brush Grout Mixer Steel Trowel/Scraper Electric Chisel Disk Cutter Hand-held Hammer & Chisel Grinder Air compressor

In accordance with Particular Specifications (Rev. 3 dated Apr-09) Section 5 Part 16 Clause 16.7, blowholes up to 15mm deep & 25mm x 25mm in dimension for buried concrete shall be acceptable & will not be repaired. For exposed surfaces, blowholes 15mm deep & 15mm x 15mm in dimension shall also be acceptable & will not require remedial action. Concrete surface should be clean, dry & free from laitance. All blow holes should be ‘opened up’ to avoid the creation of air pockets. Wire brushing shall be applied as necessary. : The hardener and base components of should be stirred thoroughly in order to disperse any settlement before mixing them together. The two components should be mixed together in a 1:1 ratio by volume, until a uniform consistency and grey colour is achieved. : After mixing, material can be taken directly from the can, or subdivided onto spot boards for individual applicators. Applications shall be done using trowel, scraper or filling knife to a satisfactory surface finish. Nitomortar FC(B) LD-CP1-SHC-MS-OW-005 Rev. 1 30-Oct-2010

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can be overcoated with all epoxy coatings after a minimum curing period of 24 hours. Prior to overcoating, the fully cured surface should be dust-free. Curing shall be performed by regularly spraying water &/or covering with wet hessian. 1.5

In accordance with Particular Specifications (Rev. 3 dated Apr-09) Section 5 Part 16 Clause 16.7 (copy attached), honeycombs up to 15mm deep & 25mm x 25mm in dimension for buried concrete shall be acceptable & will not be repaired. For exposed surfaces, honeycombs 15mm deep & 15mm x 15mm in dimension shall also be acceptable & will not require remedial action. : Defective areas shall be chipped down to sound substrate. Prepared sections up to 10mm in depth shall be repaired using Nitomortar FC(B). Concrete surfaces should be clean, dry, free from laitance & loosely adhering particles. Wire brushing shall be used as necessary. : The hardener and base components of should be stirred thoroughly in order to disperse any settlement before mixing them together. The two components should be mixed together in a 1:1 ratio by volume, until a uniform consistency and grey colour is achieved. : Prepared surfaces shall be reprofiled using the mixed material until satisfactory surface finish is achieved using steel trowel or scraper. Curing shall be performed by regularly spraying water &/or covering with wet hessian.

Prepared sections deeper than 10mm shall be repaired using Renderoc SPXtra. All contaminated, damaged or loose concrete shall be removed up to the pre-cut edge of the repair. Where reinforcements are visible, chipping shall be made up to at least 20mm behind the reinforcements to ensure adequate bonding. Edges of the section shall be roughened to provide a good mechanical key at the substrate interface. All exposed reinforcements shall be wire brushed to completely remove all loose rust. This shall be followed by water blasting to completely remove laitance, by-products of corrosion & other contaminants. : Prepared surfaces shall be primed using Nitobond AR acrylic resin-based concrete bonding agent. It must be scrubbed well into the surface using a nylon brush. : Only full bag mixing is permissible. Part mixing & addition of water to mixed material to prolong workability is not allowed. Renderoc SPXtra shall be thoroughly mixed & the temperature of the mixed material shall not exceed 30oC. 25kg. bag of Renderoc SPXtra shall be added to 4.25 to 4.5 liters of cool potable water & mixing shall be done for 3 to 5 minutes until the mix is fully homogenous using drill & paddle or forced action mixer. : The repair mortar shall be applied when the bonding agent becomes LD-CP1-SHC-MS-OW-005 Rev. 1 30-Oct-2010

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tacky, which may take 5 to 15 minutes depending on the ambient temperature. The repair mortar shall not be applied when the bonding agent is wet. Mixed Renderoc SPXtra shall be applied by trowel or gloved hand, thoroughly compacting onto the primed substrate, while the primer is still tacky, & around any exposed reinforcement. On sections having reinforcement congestion, the mixed material shall first be filled behind the reinforcement with gloved hand. If sagging occurs on vertical & overhead surfaces, the applied Renderoc SPXtra shall be completely removed. The substrate must then be reprimed & Renderoc SPXtra reapplied in layers of reduced thickness. After initial setting, the intermediate layers should be scratched-keyed & applied Nitobond AR bonding agent prior to application of the next layer of the repair material. Repaired surfaces shall be finished by striking off with a straightedge & closing with a steel or plastic float. Water can be drawn to the surface if overworking with the float occurs & an unsightly finish may result. Damp sponges or plastic floats may be used to achieve desired surface texture, but care shall be taken not to overwork the surface. After completion of finishing, the repaired section shall be applied Concure A curing compound by spray or roller. In adverse weather conditions (e.g. wind conditions or ambient temperature >30oC), supplementary curing in the form of polythene sheeting, taped down at the edges, should be used. If a smooth & non-porous finish is desired, a skim coat of Renderoc BF2 shall be applied which does not require any curing.

: Circumference of protruding tie rods shall be chipped using Electric Chisel up to a diameter of 150mm and depth of 50mm or until the tie rods can be cut at the base using disk cutter of appropriate size. The prepared substrate shall be free of oil, grease or any loosely adherent material & shall be sprayed with water prior to repair materials application. : shall be mixed to a trowellable consistency (3.4 to 3.6 liters of water per 25 kg. bag) preferably using a mechanically powered grout mixer. : Prepared surfaces shall be free of standing water & shall be filled & reprofiled using the mixed material until satisfactory surface finish is achieved using steel trowel. Curing shall be performed by regularly spraying water &/or covering with wet hessian. 1.7

: Defective areas shall be chipped down to sound substrate. Prepared sections up to 10mm in depth shall be repaired using Nitomortar FC(B). Concrete surfaces should be clean, dry & free from laitance & loosely adhering particles. Wire brushing shall be used as necessary.


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: The hardener and base components of should be stirred thoroughly in order to disperse any settlement before mixing them together. The two components should be mixed together in a 1:1ratio by volume, until a uniform consistency and grey colour is achieved. : Prepared surfaces shall be reprofiled using the mixed material until satisfactory surface finish & alignment is achieved using steel trowel or scraper. Curing shall be performed by regularly spraying water &/or covering with wet hessian. Prepared sections deeper than 10mm shall be repaired using Renderoc SPXtra. All contaminated, damaged or loose concrete shall be removed up to the pre-cut edge of the repair. Edges of the section shall be roughened to provide a good mechanical key at the substrate interface. Water blasting shall be applied if necessary, to completely remove laitance & other contaminants. : Prepared surfaces shall be primed using Nitobond AR acrylic resin-based concrete bonding agent. It must be scrubbed well into the surface using a nylon brush. : Only full bag mixing is permissible. Part mixing & addition of water to mixed material to prolong workability is not allowed. Renderoc SPXtra shall be thoroughly mixed & the temperature of the mixed material shall not exceed 30oC. 25kg. bag of Renderoc SPXtra shall be added to 4.25 to 4.5 liters of cool potable water & mixing shall be done for 3 to 5 minutes until the mix is fully homogenous using drill & paddle or forced action mixer.

: The repair mortar shall be applied when the bonding agent becomes tacky, which may take 5 to 15 minutes depending on the ambient temperature. The repair mortar shall not be applied when the bonding agent is wet. Mixed Renderoc SPXtra shall be applied by trowel, thoroughly compacting onto the primed substrate, while the primer is still tacky. If sagging occurs on vertical surfaces, the applied Renderoc SPXtra shall be completely removed. The substrate must then be reprimed & Renderoc SPXtra reapplied in layers of reduced thickness. After initial setting, the intermediate layers should be scratched-keyed & applied Nitobond AR bonding agent prior to application of the next layer of the repair material. Repaired surfaces shall be finished by striking off with a straightedge & closing with a steel or plastic float. Water can be drawn to the surface if overworking with the float occurs & an unsightly finish may result. Damp sponges or plastic floats may be used to achieve desired surface texture, but care shall be taken not to overwork the surface. After completion of finishing, the repaired section shall be applied Concure A curing compound by spray or roller. In adverse weather conditions (e.g. wind conditions or ambient temperature >30oC), supplementary curing in the form of polythene sheeting, taped down at the edges, should be used.


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If a smooth & non-porous finish is desired, a skim coat of Renderoc BF2 shall be applied which does not require any curing.

Verification of the width of cracks shall be conducted through the approved independent laboratory (Gulf Lab.). No repairs shall be made on cracks up to 0.20mm wide. Cracks wider than 0.20mm shall be repaired through crack injection using Nitofill EPLV. Concrete surfaces along the line of the cracks shall be cleaned of dust, unsound or contaminated material, plaster, oil, paint, grease, corrosion deposits or algae. The surface shall preferably be prepared using high pressure water jetting & thorough washing. Wire brushing or other mechanical means shall be applied as necessary to remove dirt. This shall be followed by applying compressed air to the cracks to ensure complete removal of all dust & loose particles. Surfaces shall be blown dry. Holes shall be drilled at suitable interval along the crack length for the insertion of injection packers. Spacing shall be close enough to ensure that resin will penetrate along the crack to the next point of injection. The surface of the cracks between packers shall be sealed with a band of Nitomortar FC, 30mm to 40mm wide & 2mm to 3mm thick. Applied Nitomortar FC shall be allowed to adequately cure. This shall be followed by the injection of the mixed injection resin at a pressure of at least 0.40 MPa (4 bars). Injection shall continue until the resin appears on the next port.

The hardener & base component of the injection resin shall be mixed thoroughly until the liquid becomes clear. Following completion of the injection works, the repaired section shall be allowed to cure for 24 hours & shall be left undisturbed for this period. Packers shall then be removed & holes/voids to be made good using Nitomortar FC & allowed to cure. Surface protrusions of Nitomortar FC shall be ground off.





Personnel engaged with this works shall follow safety and health Plan; Safety & Health Manager shall arrange one safety person to checking and Monitoring safety and health. To follow Sinohydro Contractor’s Safety and Health management plan, please refer to Document: Safety and Health Plan Rev.4 (No. LD-CP1-SHC-HSP-0015)


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Concrete Repairs


Vehicles falling from the edge of the excavation

Contractors’, Subcontractors All personnel on this site Operators

Injury, Fractures, Cuts, Bruises

Rigid safety barriers shall be erected around all excavations to prevent vehicles falling into them. Vehicles shall be kept away from excavations wherever possible. Project/Construction Where vehicles have to tip materials into excavations, Manager/s stop blocks to prevent them from over-running shall be & Supervisors used and a banksman shall be present before discharging the load.

Vehicles reversing



Where vehicles have to reverse they shall be controlled by properly trained banksman

Project/ Construction Manager/s & Supervisors

During the hours of darkness all the excavations and other working areas shall be adequately illuminated and warning lights about the excavation shall be placed to ensure safety of pedestrians and the vehicular traffic. Night work hours shall be structured to comply with all rules and regulations.


There should be safe means of access or escape to all the working areas, above or below ground level. This can be a ladder, ramp, stairs and etc. It shall also be kept well lit, clear of obstructions and well maintained.


Night works lighting

Contractors’, Subcontractors and All personnel on Accidents this site Operators

Improper access



Contractors’, Subcontractors Steel reinforcement All personnel on this site Operators

Fractures, Cuts, Bruises

Pump and Operation

Fractures, Cuts, Bruises

Boom

Contractors’, Subcontractors



Concrete Pouring

Project/ Construction Manager/s & Supervisors Project/ Construction Manager/s

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All personnel on this site Operators Contractors’, Subcontractors All personnel on this site Operators


To minimize cuts from reinforcement bar ends the following shall be supllied.PPE for the required task. Suitable strong and flexible leather gloves. When walking on deck care shall be taken to eliminate slipping on wet surfaces. Sharp edges on ends of steel reinforcement shall be tuned down. Concrete pump and boom operators should be competent to safely operate relevant equipment.

Competence is achieved through training and supervision and should be assessed by testing both theoretical & Supervisors knowledge and physical operation of t he machinery Fractures, Cuts, Bruises

The rubber delivery hose should always be checked for damage prior to being fitted. Care should be taken to avoid damage to the hose during use. Use a hose that has a pressure rating. Always wear PPE.

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Concrete Pouring


All personnel on this site Operators Contractors’, Subcontractors All personnel on this site Operators





Competence is achieved through training and supervision and should be assessed by testing both theoretical & Supervisors knowledge and physical operation of t he machinery Fractures, Cuts, Bruises

The rubber delivery hose should always be checked for damage prior to being fitted. Care should be taken to avoid damage to the hose during use. Use a hose that has a pressure rating. Always wear PPE.


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All employees engaged in this works shall follow the Environment Management Plan (Doc. No. LD-CP1-SHC-EHC-OC-0135). Environment Manager shall arrange one person to check and monitor site environment.

Sinohydro Quality Assurance Plan (Doc. No. LD-CP1-SHC-QAP-001) 1.10

Testing and inspections shall be performed by Sinohydro in accordance with Doc. No. LDCP1-SHC-QAP-015 Rev. 1 “Inspection & Testing Program”.

1. Appendix 1: RFI 2. Appendix 2: Product Data Sheets for Nitomortar FC(B), Conbextra GP, Nitofill EPLV, Renderoc SPXtra, Nitobond AR, Concure A & Renderoc BF2.





All employees engaged in this works shall follow the Environment Management Plan (Doc. No. LD-CP1-SHC-EHC-OC-0135). Environment Manager shall arrange one person to check and monitor site environment.

Sinohydro Quality Assurance Plan (Doc. No. LD-CP1-SHC-QAP-001) 1.10

Testing and inspections shall be performed by Sinohydro in accordance with Doc. No. LDCP1-SHC-QAP-015 Rev. 1 “Inspection & Testing Program”.

1. Appendix 1: RFI 2. Appendix 2: Product Data Sheets for Nitomortar FC(B), Conbextra GP, Nitofill EPLV, Renderoc SPXtra, Nitobond AR, Concure A & Renderoc BF2.


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RFI Number LD-CP1-SHC-ITPSINOHYDRO CORPORATION To

Halcrow

Cc Type of Work Location Method with reference to ITP/drawings Inspection time

Inspection Date

Comments

APPROVED

Yes

No

Requested by

Received by

Site Engineer/Subcontractor

QC Engineer

QC Manager

Admin Representative

Name:

Name:

Name:

Name:

Signature:

Signature:

Signature:

Signature:

Date:

Date:

Date:

Date:

Company :(

)


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6.Method Statement for Concrete Repairs Rev. 1

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